The present invention relates to improvements for closure devices for dispensing containers. Since closure devices must be compatable with the containers they are to enclose, several types of dispensing containers on which the improved closure devices provided by the present invention may be utilized will be discussed briefly. This will indicate the versatility and adaptability of closure devices of this invention.
Dispensing containers are presently used by the fast food industries and others for dispensing liquid and other flowable products. The shapes of the sidewalls of most of these containers are similar to those of sections cut from cones by two planes which lie perpendicular to the axes of the cones. The smaller ends of the containers are usually closed during the manufacturing process. The other ends which will be referred to as the top ends are generally sealed when the container is filled.
Most present dispensing containers are stamped or molded from plastic or foam materials or are formed from sheets of plastic or specially coated cardboard. The sidewalls are usually rolled outward or thickened at their tops to stiffen their rims. The resulting rims also facilitate the capping operations and provide a more pleasant touch to the users lips.
Most present dispensing containers are of the disposable type thus requiring that manufacturing costs be kept within a relatively low price range. These containers are usually capped with push-on pull-off type lids when capping is required.
Present closure devices for these dispensing containers vary somewhat in shape and structure and special features but most of them function in the same manner. Their top surfaces or plates, are usually in the shape of thin generally flat discs. They usually have special ridges and indentions and other features such as perforations for pull-out tabs and small punctures for air vents and various lettering. The top plate either seats on the top rim of the container to help effect a seal or it supports a ring or rings which provide surfaces which similarly serve that purpose.
Most present closure devices are equipped with what will be called an outer gripping ring, although some present closure devices use only what will be referred to as an inner gripping ring. Many present closure devices use both an inner and outer gripping ring and may also use what will be referred to as a support ring. These somewhat tapered gripping rings are flexible to some extent and are sized to fit relatively tightly on the rim of the enclosed container. They are thus capable of holding the enclosure devices in place on the attached containers. These rings normally also form a seal with the contacting inner and outer surfaces of the container wall.
Support rings connect the top plate to the inner gripping ring. It is often specially shaped to enable it to be compressed during placement of the closure device on the container so as to be capable of maintaining outward pressure on the inner gripping ring.
A preferred embodiment of the invention may be stamp molded from plastic and is comprised of a thin circular top plate. The edges of the top plate curve downward and extend downward at varying slopes to form a support ring. The support ring curves outward and upward and extends upward at varying slopes to form the inner gripping ring. The inner griping ring curves outward and extends generally outward to form a seat to fit against the top surface the rim of an enclosed container. It then curves downwardly and extends generally downward at varying slopes to form the outer gripping ring.
Present closure devices for dispensing containers function effectively. They do not allow the contents of the container to leak excessively and they do not fall off. They are attractive enough and since they are stamp molded they can be produced at costs which makes them suitable for disposable usage.
In spite of all this, very few users like them although food chains make sure that they are placed on all take out orders. Many of their customers would prefer that they be left off. Present closure devices are just too much trouble to take off. And doing so, particularly while .sitting is too risky. This is especially true for children. Gripping a container firmly enough to hold on to it while pulling the lid off without tilting or crushing the container is a difficult task and when the lid suddenly pops off, spillage occurs.
Adults have problems removing the lids too especially while driving. The operation requires the use of both hands and a good bit of attention. It is quite possible for a driver to look back up after having removed a lid to find the vehicle encroaching into the wrong lane or headed for the ditch, or worse. Then after the lid is removed there is the problem of finding a place to put the lid so it will not soil something or get soiled. So the lids usually end up on the floor or out a window and the user is often left with an uncovered container to hold on to. Admittedly there are present closure devices with perforations for tearing out a small section of the top for sipping, but removing them from a closed container filled with hot coffee is difficult and tedious and attention diverting and risky. Reclosing them is almost impossible.
Then too, people do not like to drink or sip through a hole in a container lid. They much prefer using the lip of the container. They also prefer not having to tilt their heads back at some awkward angle as is usually required when drinking through a hole in a lid.